EP0559775B1

EP0559775B1 - Contact lens case venting system

Info

Publication number: EP0559775B1
Application number: EP92901245A
Authority: EP
Inventors: Rowland W. Kanner
Original assignee: Ciba Vision Corp
Current assignee: Ciba Vision Corp
Priority date: 1990-11-30
Filing date: 1991-11-19
Publication date: 1996-08-28
Anticipated expiration: 2011-11-19
Also published as: JPH07500426A; EP0559775A4; DE69121726T2; EP0559775A1; ATE142033T1; WO1992009942A1; DE69121726D1; AU9062791A; CA2097290A1; AU655955B2

Abstract

An appliance (10) for disinfecting contact lenses (24) wherein the lenses are disposed within a disinfecting solution (28) which liberates gas (A) during the disinfecting action, includes a container body (12) for immersion of the lenses within the disinfecting solution (28) and a removable cap (14) closing the container body (12). The appliance further includes a normally closed vent conduit (30, 42) for passage of the pressurized effluent gas (A) from the container body (12) through the cap (14), and within the vent conduit is a check valve (32) including a disc member (34) having a slit (36) therethrough which opens for vent discharge of the gas (A) with sufficient pressure on the disc exerted by the gas during passage through the vent conduit, after which the slit (36) recloses to prevent any subsequent leakage of the solution (28) therethrough.

Description

Background of the Invention

This invention relates to container appliances for chemical sterilization of small articles such as contact lenses, and more particularly, relates to pressure relief venting of such appliances.
The well-known, commercialized contact lens disinfection process employing hydrogen peroxide solution as a bactericide is described for example in U.S. Patent No.s 4,750,610; 4,889,693; and 4,956,156. In such process, the contact lenses are immersed overnight in an aqueous solution of hydrogen peroxide which is catalytically decomposed during the sterilization process resulting in liberation of oxygen gas. As a result, the liberated oxygen produces a pressure increase within the disinfecting vessel which is accordingly provided with venting structure for relief of the pressure to the ambience. Further, in US 3,527,376 is described an arrangement in which a diaphragm is clamped between upper and lower portions of a cap and seats in a recess formed in the lower portion of the cap.
The present invention provides simplified reliable, venting structure in such pressurized vessels particularly for low pressure discharge of the gas. The invention would of course be usable with any disinfecting process wherein a gaseous material is liberated during the process.

Summary of the Invention

In accordance with the present invention, there is provided an appliance for disinfecting contact lenses or the like wherein the lenses are disposed within a disinfecting solution which liberates a gas during the disinfecting process including a normally closed vent conduit for passage of pressurized effluent gas from a container body through a removable cap; and
a check valve in said normally closed vent conduit including a disc member having a slit therethrough which opens for vent discharge of said pressurized effluent gas by sufficient pressure on said disc member exerted by said pressurized effluent gas during passage through said normally closed vent conduit, after which said slit recloses to prevent any subsequent leakage of any disinfecting solution therethrough, CHARACTERIZED IN THAT said cap includes a supporting surface against which said closed slit is engaged when closed, and from which said slit disengages when opened to form a one-way venting valve.
Further and preferred features of the invention are as follows.
The cap may comprise upper and lower portions and wherein said support surface is formed within a recess in said lower cap portion. The disc member may be clamped between a supporting shoulder formed in said lower cap portion and securing projection from said upper cap portion. The securing projection may comprise a ring extending from said upper cap portion. The lower cap portion may include at least one through passageway having one end opening against said disc member and a second end opening to communicate with said pressurized effluent gas within said container body to form a portion of said vent conduit enabling said exertion of said pressurized effluent gas against said disc member to open said slit. The lower cap portion may include a plurality of through passageways opening against said disc member respectively spaced from said slit. The disc member may have a generally circular configuration and said slit linearly aligned along a diameter of said disc member at a generally central location, and said plurality of through passageways may be arranged to open against said disc member in a radially symmetrical pattern relative to said slit. The appliance may further comprise lens holder means for supporting contact lenses within said container body.

Brief Description of the Drawings

FIG. 1 is a sectional view of one embodiment of a lens sterilizing appliance in accordance with the present invention;
FIG. 2 is a fragmentary sectional view taken from FIG. 1 illustrating passage of gas through an opened check valve formed in the cap of the appliance; and
FIG. 3 is a plan view of the check valve disc shown in FIGS. 1 and 2.

Detailed Description of the Illustrated Embodiment

Referring now in more detail to FIGS. 1 and 2, one embodiment of the contact lens disinfecting appliance in accordance with the present invention is generally designated by reference character 10. The appliance 10 includes a generally cylindrical container body 12 having a threaded end opening for receiving a removable screw cap 14. As best shown in FIGs. 1 and 2, a lower portion of cap 14 includes a closure flange 16 having an upwardly projecting tongue 16a which is secured in a mating mortise, for example, by sonic welding. The closure disc or flange 16 has a grooved periphery within which an annular gasket 18 is secured. The gasket 18 seals against the end rim 20 at the opening of the container body 12. A depending lens-supporting frame 22 is secured to and projects downwardly into the cavity within the cylindrical container body 12 when the cap 14 is mounted thereon. A pair of contact lenses 24 are enclosed and supported by the frame 22 and respective pivotal baskets 26 (one of which is illustrated) as more fully described in U.S. Patent No. 4,750,610, the text of which is incorporated by reference herein. The baskets 26 are perforated to allow passage of the disinfecting liquid such as hydrogen peroxide solution 28 within which the lenses 24 are immersed.
In the disinfecting process, the hydrogen peroxide solution is poured into the container body 12 and the cap 14 is threaded thereon to seal the gasket 18 against the rim 20 as shown in FIG. 3, thereby immersing the lenses 24 within the solution. A catalytic element 13 initiates decomposition of the hydrogen peroxide solution and as the disinfecting reaction proceeds, the liberated oxygen exerts progressively elevated pressure within the container body 12.
In order to vent the elevated pressure generated within the container body 12, the cap 14 is provided with a vent passageway 30 which opens through the top of the cap 14 and a venting check valve structure generally designated by reference character 32 which leads from the interior of the container body to the vent passageway 30. The check valve structure 32 includes a valve disc 34 with a generally centrally located slit 36 as best shown in FIG. 3. The disc 34 is seated on a recess 38 formed within the cap flange 16. As best shown in FIG. 2, the vent structure 32 and passageway 30 are offset in relation to the centrally positioned lens support frame 22. The disc 34 is peripherally clamped against the flange recess 38 by an overlying ring 40 which is molded to downwardly project from the upper portion of the cap 14.
As best shown in FIG. 1, the normally closed valve slit 36 is seated upon the central surface 39 of the seating recess 38 which also has a plurality of vent ports 42 which pass through the cap flange 16 and open against the valve disc 34 spaced from the valve slit 36.
When the elevated pressure of the liberated oxygen gas is communicated through the ports 42 against the disc 34 as shown in FIG. 2, the upwardly directed gas flow indicated by arrows A will lift and upwardly deflect the central portion of the disc 34 to open the slit 36 allowing passage of the gas upwardly through the open slit leading to the passageway 30 and discharge therefrom to the ambience. Following gas discharge to sufficiently reduce the pressure within the container 12, the deflected central portion of the disc 34 will downwardly redeflect to reclose the slit 36 against the surface 39 of the recess 38 again in the position shown in FIG. 1 so that the closed slit will prevent any subsequent leakage of solution or entry of air. The slitted disc 34 functions as a one-way check valve and allows only vent discharge of pressurized gas. As a result, the closed slit also prevents any backflow and entry of bacterial or other contamination into the interior of the container, while automatically opening to vent subsequently generated excessive gas pressure.
The valve disc 34 can be fabricated, for example, from typical elastomeric composition such as silicone rubber. In typical lens sterilization containers, a silicone rubber disc in a grade of 50 durometer and dimensioned approximately 0.30 inch in diameter and 0.030 inch thick wit a slit of approximately 0.060 inch has performed to open at a threshold pressure in the range of approximately 6-8 psig and enabled a vent gas flow rate of approximately 30 cc's per minute at pressures of approximately 25 psig.

Claims

An appliance (10) for disinfecting contact lenses (24) or the like wherein the lenses are disposed within a disinfecting solution (28) which liberates a gas (A) during the disinfecting process including a normally closed vent conduit (30,42) for passage of pressurized effluent gas (A) from a container body (12) through a removable cap (14); and
a check valve (32) in said normally closed vent conduit including a disc member (34) having a slit (36) therethrough which opens for vent discharge of said pressurized effluent gas by sufficient pressure on said disc member exerted by said pressurized effluent gas during passage through said normally closed vent conduit, after which said slit (36) recloses to prevent any subsequent leakage of any disinfecting solution (28) therethrough, CHARACTERIZED IN THAT said cap (14) includes a supporting surface (39) against which said closed slit (36) is engaged when closed, and from which said slit (36) disengages when opened (Fig. 2) to form a one-way venting valve.
An appliance according to claim 1, wherein said cap comprises upper and lower portions and wherein said support surface is formed within a recess (38) in said lower cap portion.
An appliance according to claim 2, wherein said disc member (34) is clamped between a supporting shoulder formed in said lower cap portion and a securing projection (40) from said upper cap portion.
An appliance according to claim 3, wherein said securing projection (40) comprises a ring extending from said upper cap portion.
An appliance according to claim 1, wherein said lower cap portion includes at least one through passageway (42) having one end opening against said disc member (34) and a second end opening to communicate with said pressurized effluent gas within said container body (12) to form a portion of said vent conduit (30,42) enabling said exertion of said pressurized effluent gas against said disc member (34) to open said slit (36).
An appliance according to claim 5, wherein said lower cap portion includes a plurality of through passageways (42) opening against said disc member (34) respectively spaced from said slit (36).
An appliance according to claim 6, wherein said disc member (34) has a generally circular configuration and said slit (36) is linearly aligned along a diameter of said disc member (34) at a generally central location, and said plurality of through passageways (42) are arranged to open against said disc member (34) in a radially symmetrical pattern relative to said slit (36).
An appliance according to claim 1, further comprising lens holder means for supporting contact lenses within said container body (12).